Evaluation of the effect of oil-fraction type (oil or oleogel) on the textural properties of proteins and gellan gum acid-induced emulgels by a mixture design approach

Abstract

The textural properties (penetration, compression, and extrusion) of acid-induced emulgels composed of sodium caseinate, soy protein isolate, and gellan gum were determined employing a mixture design approach. The type of oil-fraction effect, edible oil or candelilla wax oleogel, in emulgels was also determined. In general, emulgels with candelilla wax oleogel as oil fraction presented a softer, less cohesive, and less firm texture, resulting from the higher emulsion stability provoked by candelilla wax, requiring less protein to form the emulsion. The relatively higher protein available affected the gel structure formation since, in the acidic conditions in the systems, the formation of ductile protein aggregates was disadvantaged, since pH was close to their isoelectric point. Gellan gum dominated the acid-induced gel, with certain interaction with acid-altered proteins. The acid-induced gelation of composite emulsions offers the possibility to develop different textures employing different types of oil-fractions. These systems can be employed to replace fat in processed foods like yogurts.